The prior art Venetian blinds include a series of parallel slats that can be tilted to either open or close visual passage of light from one side to the other side of the blinds. Venetian blinds typically include an upper stationary support rail for mounting to the upper frame of a window and a lower movable support rail, with the slats suspended between the support rails, and pull cords that extend upwardly from the reach of the person operating the blinds to the upper rail then downwardly from the upper rail through openings in the parallel slats to the lower rail. When the person pulls the cords, the bottom rail is pulled upwardly and progressively collects the slats to lift them higher to raise the blinds.
While Venetian blinds have been known and used for many decades, most of them have included the lifting cords described above, which is a concern in the industry because there have been several deaths or near deaths of children that have inadvertently become entangled in the lift cords and have been choked. Further, when the lift cords are pulled downwardly, a significant downward force is applied by the pull cords to the supporting upper rail and its components, which tends to pull the upper rail away from the supportive wall structure. This requires that the upper rail be very securely constructed and securely attached to the window frame and allows the person operating the Venetian blinds to apply significant downward force on the lift cords to lift the lower slats toward the top of the window frame.
When the pull cord has been pulled to lift the lower rail and its adjacent slats to the desired elevation, the operator must manipulate the pull cord while the pull cord holds the slats at the desired position to engage a catch in the upper rail. This prevents the pull cord from allowing the slats and lower rail to move uncontrollably down. But the higher the blinds are raised the more the pull cord is moved downwardly within the reach of children, increasing the hazard of access and injury to children.
Even with the blinds in their fully lowered position with the pull cords out of reach of children, the portion of the pull cords that extend through the slats can still be reached by children. This is known as an accessible inner cord.
Other means have been developed that have attempted to solve the above described problems, but there still remains a need to have affordable cordless Venetian blinds to avoid the hazards, inconvenience and non-durability of the structure that comprises the blinds, and the need to provide cordless blinds and to omit the downward force that is required to raise the blinds.